With the rapid development of Internet and the popularity of big-screen multi-function mobile terminals, a lot of mobile data multimedia services and various high-bandwidth multimedia services have emerged, such as video conference, television broadcast, video on demand, advertisement, online education, interactive game and the like; this aspect not only meets the requirement of a mobile user on multiple services, but also brings a new business growth to a mobile operator. These mobile data multimedia services require that multiple users can receive the same data simultaneously, and have advantages of big data amount, long duration; delay sensitivity and the like compared with a general data service.
In order to utilize a mobile network resource effectively, the 3rd Generation Partnership Project (3GPP) proposes an MBMS service that is a technology for transmitting data from one data source to a plurality of target mobile terminals; this technology realizes sharing of network resources (including a core network and an access network) and improves the utilization rate of the network resource (particularly an air interface resource). The MBMS service defined by the 3GPP not only can realize multicast and broadcast of messages of low-rate plain texts, but also can realize multicast and broadcast of high-rate multimedia services and provide a variety of videos, audios and multimedia services. The MBMS service undoubtedly follows a trend of the future development of mobile data and provides a better business prospect for the development of 3G.
At present, the MBMS technology is introduced in a Release 9 (R9) of a Long Term Evolution (LTE) system and is enhanced in a Release 10 (R10). In the R9, control signaling and user data of the MBMS service are separately transmitted and are respectively called a Control Plane (CP) and a User Plane (UP). The CP controls the sending of the UP data by controlling start, update and end of a service, so as to implement the sending of the basic MBMS service. The MBMS service is sent in an MBMS Single Frequency Network (MBSFN) area (statically or semi-statically configured) with a fixed size. In the R10, in order to improve the resource utilization rate of an MBMS system and to facilitate the management of an operator, the MBMS technology is enhanced, mainly including the following two enhancements:
1. Introduction of an MBMS Counting mechanism. The main principle of the MBMS Counting mechanism is that: a Multi-cell/multicast Coordination Entity (MCE) sends a Counting request of some MBMS service to an evolved NodeB (eNB) through an M2 interface; the eNB sends the Counting request to a UE on a Multicast Control Channel (MCCH); the UE that is receiving the MBMS service in a connected state feeds back to the eNB a receiving state of the MBMS service being received by the UE; and then eNB reports the feedback result to the MCE. The purpose of the introduction of the Counting mechanism is to facilitate an operator to count the receiving state of some MBMS service and suspend/resume (or activate/deactivate) the service according to the receiving state, so as to improve the utilization rate of radio network resources.
2. Introduction of a service priority based resource pre-emption technology, namely, Allocation and Retention Priority (ARP). The main principle of the resource pre-emption technology is that: when a resource is tense, an MBMS service with a higher priority can pre-empt the resource of another MBMS service with a lower priority. When the resource is pre-empted by the service with a higher priority, the service with a lower priority is suspended; when a network has a new radio resource, the suspended service can be resumed to be sent.
Both the counting and the resource pre-emption are initiated by the MCE; the range of the counting and the resource pre-emption generally is in a Multicast Broadcast Single Frequency Network (MBSFN) area. The MBMS service being suspended means that: the MCE notifies the eNB to release a corresponding radio resource; a corresponding service context in the eNB is reserved; the eNB may exit or not exit a corresponding IP multicast group; after suspension, the UE stops periodically reading an MCCH message but monitors an MCCH notification message corresponding to the MBMS service. The MBMS service being resumed means that: the MCE notifies the eNB to reallocate a radio resource, if the eNB has exited the IP multicast group, the eNB rejoins the IP multicast group, continues transmitting the MBMS service adopting an MBSFN mode and periodically reads the MCCH message.
An ARP parameter involved in the resource pre-emption comes from an Evolved Packet Core (EPC) and can be sent to the MCE from an M3 interface through an MBMS session station request message.
During the study and practice process of the present technology, it is found that the present technology has problems as follows: a 3GPP Rel-10 MBMS adopts an MCCH change notification (hereinafter called MCCH notification) mechanism, that is, a change of an MCCH is indicated by using a specific MBMS Radio Network Temporary Identifier (M-RNTI) and Downlink Control Information (DCI) on a Physical Downlink Control Channel (PDCCH); here, the change is only for a session start or counting request event, that is, a network side sends an MCCH notification message only when the session start or counting request event occurs; if the MCE suspends a certain MBMS service according to a counting report or an ARP requirement, for a UE that is receiving or interested in receiving the MBMS service, the MBMS service is stopped; the UE monitors the MCCH notification message and waits a restart of the service. After a period of time, the MBMS service above is resumed; however, the MCCH notification at this moment cannot indicate that the service is resumed, and the UE does not continue reading content on the MCCH periodically, thus the UE cannot know that the MBMS service has been resumed; therefore, the UE cannot receive the resumed MBMS service immediately.